Chemistry Answers

1.     Determine the pH of a buffer prepared by adding 15 mL of 0.25 M acetic acid to 35 mL of 0.17 M sodium acetate. Given Ka for acetic acid = 1.7 x 10^-5.

Consider the potentiometric titration of 100.0 mL of 0.0100M Ce 4+in 1M HClO 4by

0.0400M Cu + to give Ce 3 + and Cu 2 + using Pt and saturated Ag|AgCl electrodes to find the end point. ( 15 marks)

a. Write a balanced titration reaction.

b. Write two different half-reactions for the indicator electrode.

c. Write two different Nernst equations for the cell voltage.

d. Calculate E at the following volumes of Cu + : 1.00, 12.5, 24.5,

25.0, 25.5, 30.0, and 50.0 mL. Sketch the titration curve

Calculate the pBa of 50 mL of 0.035M of Na2SO4 added with 0.0500 M BaCl2 of the following

volume

a. 15

b. 25

c. 33

d. 35

e. 38

f. 45

g. 50

Then, generate the graph of the titration curve of the system ( BaCl2 vs pBa)

(a.) Calculate the pH of the solution that is 0.100 M methylamine (NH2CH3) and 0.400 M of

sodium methyalamine

(b.) Calculate the pH change when 80 mL of 0.15 KOH is added to the 100 mL solution stated

above (a)

(c.) Calculate the pH change when 80 mL of 0.10 HNO3 is added to the 100 mL solution

stated above (a)

Calculate the pH of 50 ml of 0.1000 M methylamine solution after the following volume of 0.1000 M HNO3, where added 60

Calculate the pH of 50 ml of 0.1000 M methylamine solution after the following volume of 0.1000 M HNO3, where added 55

Calculate the pH of 50 ml of 0.1000 M methylamine solution after the following volume of 0.1000 M HNO3, where added 50

Calculate the pH of 50 ml of 0.1000 M methylamine solution after the following volume of 0.1000 M HNO3, where added 3

Calculate the pH of 50 ml of 0.1000 M methylamine solution after the following volume of 0.1000 M HNO3, where added 25